June 2025 - Integument double-feature

It's time for our June newsletter! In this one, we've got a double-feature for our integument project.

In April, we tied off the descriptive part of the project, with our Properties of Feathers chapter. Since then, we have turned our attention to molecular regulation. There's a lot of detail we need to understand in order to engineer fur, feathers, and scales. While the way these structures grow naturally, starting from embryonic development, won't be exactly what we need to do in adult patients, some processes and molecular signals will be highly relevant.

Any research paper, by its own, might only reach a conclusion that, for example, a gene called FGF5 regulates hair length. Things like those are crucial to learn, but they still represent separated islands of information. We are pulling these and other processes into one place, working to understand the key decisions that cells make as they progress from stem cells (in hair follicles, feather follicles, or layers of stem cells in skin or scales), through various kinds of maturing and living cells, to the fate that meets most cells of the integument - programmed cell death through keratinization/ cornification. They talk with each other, attach or detach from each other, push or pull against each other in coordinated ways, and go through maturation processes. All of these things result in fur, feathers, and scales that renew themselves - so we absolutely want to 'cheat' off of what biology does for our engineering.

The articles in this newsletter add an intense and necessary level of detail to the molecular knowledge we've been assembling. The first article, written by Lathreas, discusses how sheets of cells can change shapes in coordinated ways. This is useful for a lot of skin structures, like when hair follicles invaginate, or when some the crevasses between some types of scales form. The second article, written by Tilt Wolf, covers a variety of molecular signaling pathways involved in regulating hair length and width, and reasons through some pathways we may prefer to target instead of other pathways that might appear functionally similar.

Thank you as always for helping make our work possible.

PS - Head anatomy videos are getting closer, but not ready yet!

PPS - Hope yall enjoy the new site navigation! (or at least don't hate it :P) Still needs refinement, but it was long overdue, we've got a toooon of information on the website now, and it needed a better navigation method. More rationale on this in next month's newsletter!